It is possible.
Just set up the router to work in AP-Client mode in the wireless setup. Make sure you put the same SSID and the MAC address of AP(192.168.6.x). Then go to Setup --> Basic setup and put address 192.168.6.z for IP, and 192.168.6.x for gateway. For DNS - whatever DNS servers you use.
Then on Network Setup put 192.168.2.y for IP. That is the IP you should use for gateway on your 192.168.2.1-254 network. DNS - whatever DNS servers you use.